Mechanical Heart Valves: History, Types and What Patients Should Know

Tetralogy of Fallot is one of the commonest procedures in paediatric cardiac surgery, alongside ASD and VSD repair. It is a very commonly performed procedure with excellent outcomes — any paediatric cardiac centre does this routinely, and the clinical outcomes are excellent.

The patient should be referred for further evaluation at the appropriate time — not too early, but also not too late, because if it is too late the patient develops more comorbidities and the outcome may not be as good. For valve disease specifically, there are definite guidelines for mitral and aortic valve disease on when a patient should be referred for cardiac surgery; whether it can be done locally depends on whether it looks like a straightforward repair or replacement, or a more challenging one. The two important criteria are the patient's clinical symptoms — which functional class (1, 2, 3, or 4) — and the echo findings, which show the severity of stenosis or regurgitation, LV function, and pulmonary artery pressures. Together these decide whether the patient should be referred for surgical treatment, locally or elsewhere.

Cost primarily depends on two things: which valve is used — mechanical valves are significantly less expensive than tissue valves, and among tissue valves, third-generation valves cost more than second-generation ones — and the patient's clinical course, since a straightforward surgery without a long hospital stay or comorbidities costs less. The average cost generally starts from $9,000 and goes up to $15,000–$16,000.

Cardiac tumours in children are well known, though this exact pathology is not very common. The echo gives us an idea, but I would suggest also doing an MRI and a CT to further delineate it. I would like the details of this patient sent to our institute so we can forward it to our paediatric cardiac surgeon, since paediatric cardiac surgery is a separate subspecialty from the adult cardiac surgery I practise, and we do have a dedicated paediatric cardiac surgical team. This child needs very close follow-up and further investigation.

Tetralogy of Fallot is one of the commonest surgical procedures, and the outcome depends on the exact anatomy delineated by a proper paediatric echo, but six years is not a very late stage — in India a lot of patients are operated on at this age or even older. The outcome of tetralogy repair even at 6 years is excellent, so this patient certainly needs surgical correction.

Cardiac surgeon Albert Starr worked with engineer Lowell Edwards to invent the ball and cage valve. Dr. Starr performed the first mechanical valve placement in 1960, and the valve became commercially available in 1964.

Bileaflet valves are now the most commonly used mechanical heart valves worldwide, performing better than the older single leaflet designs.

The TTK Chitra valve is a tilting disc mechanical valve manufactured in India, used in India and other countries.

The ball and cage valve was eventually discontinued because it is bulky, now that better valve designs are available, even though patients who received it more than three decades ago still return for follow-up today.